Deng Zhe, Xu Xiao-Yan, Yunita Fenny, Zhou Qing, Wu Yong-Rong, Hu Yu-Xing, Wang Zhi-Qi, Tian Xue-Fei
Department of Internal Medicine, College of Integrated Chinese and Western Medicine, Hunan University of Chinese Medicine, Changsha 410208, Hunan Province, China.
Hunan Key Laboratory of Translational Research in Formulas and Zheng of Traditional Chinese Medicine, Hunan University of Chinese Medicine, Changsha 410208, Hunan Province, China.
World J Gastrointest Oncol. 2020 Oct 15;12(10):1091-1103. doi: 10.4251/wjgo.v12.i10.1091.
Liver cancer is the sixth most frequently occurring cancer in the world and the fourth most common cause of cancer mortality. The pathogenesis of liver cancer is closely associated with inflammation and immune response in the tumor microenvironment. New therapeutic agents for liver cancer, which can control inflammation and restore cellular immunity, are required. Curcumin (Cur) is a natural anti-inflammatory drug, and total ginsenosides (TG) are a commonly used immunoregulatory drug. Of note, both Cur and TG have been shown to exert anti-liver cancer effects.
To determine the synergistic immunomodulatory and anti-inflammatory effects of Cur combined with TG in a mouse model of subcutaneous liver cancer.
A subcutaneous liver cancer model was established in BALB/c mice by a subcutaneous injection of hepatoma cell line. Animals were treated with Cur (200 mg/kg per day), TG (104 mg/kg per day or 520 mg/kg per day), the combination of Cur (200 mg/kg per day) and TG (104 mg/kg per day or 520 mg/kg per day), or 5-fluorouracil combined with cisplatin as a positive control for 21 d. Tumor volume was measured and the protein expression of programmed cell death 1 and programmed cell death 1 ligand 1 (PD-L1), inflammatory indicators Toll like receptor 4 (TLR4) and nuclear factor-κB (NF-κB), and vascular growth-related factors nitric oxide synthases (iNOS) and matrix metalloproteinase 9 were analyzed by Western blot analysis. CD4CD25Foxp3 regulatory T cells (Tregs) were counted by flow cytometry.
The combination therapy of Cur and TG significantly inhibited the growth of liver cancer, as compared to vehicle-treated animals, and TG showed dose dependence. Cur combined with TG-520 markedly decreased the protein expression of PD-L1 ( < 0.0001), while CD4CD25Foxp3 Tregs regulated by the PD-L1 signaling pathway exhibited a positive correlation with PD-L1. Cur combined with TG-520 also inhibited the cascade action mediated by NF-κB ( < 0.0001), thus inhibiting the TLR4/NF-κB signalling pathway ( = 0.0088, < 0.0001), which is associated with inflammation and acts on PD-L1. It also inhibited the NF-κB-MMP9 signalling pathway ( < 0.0001), which is associated with tumor angiogenesis.
Cur combined with TG regulates immune escape through the PD-L1 pathway and inhibits liver cancer growth through NF-κB-mediated inflammation and angiogenesis.
肝癌是全球第六大常见癌症，也是癌症死亡的第四大常见原因。肝癌的发病机制与肿瘤微环境中的炎症和免疫反应密切相关。需要能够控制炎症并恢复细胞免疫的新型肝癌治疗药物。姜黄素（Cur）是一种天然抗炎药物，人参总皂苷（TG）是一种常用的免疫调节药物。值得注意的是，Cur和TG均已显示出具有抗肝癌作用。
确定Cur与TG联合使用在皮下肝癌小鼠模型中的协同免疫调节和抗炎作用。
通过皮下注射肝癌细胞系在BALB/c小鼠中建立皮下肝癌模型。动物分别用Cur（每天200mg/kg）、TG（每天104mg/kg或520mg/kg）、Cur（每天200mg/kg）与TG（每天104mg/kg或520mg/kg）联合治疗，或用5-氟尿嘧啶联合顺铂作为阳性对照，治疗21天。测量肿瘤体积，并通过蛋白质印迹分析检测程序性细胞死亡蛋白1和程序性细胞死亡蛋白1配体1（PD-L1）的蛋白表达、炎症指标Toll样受体4（TLR4）和核因子-κB（NF-κB），以及血管生长相关因子一氧化氮合酶（iNOS）和基质金属蛋白酶9。通过流式细胞术对CD4CD25Foxp3调节性T细胞（Tregs）进行计数。
与溶剂处理的动物相比，Cur与TG联合治疗显著抑制了肝癌的生长，且TG呈剂量依赖性。Cur与TG-520联合使用显著降低了PD-L1的蛋白表达（<0.0001），而由PD-L1信号通路调节的CD4CD25Foxp3 Tregs与PD-L1呈正相关。Cur与TG-520联合使用还抑制了由NF-κB介导的级联反应（<0.0001），从而抑制了与炎症相关并作用于PD-L1的TLR4/NF-κB信号通路（=0.0088，<0.0001）。它还抑制了与肿瘤血管生成相关的NF-κB-MMP9信号通路（<0.0001）。
Cur与TG联合使用通过PD-L1途径调节免疫逃逸，并通过NF-κB介导的炎症和血管生成抑制肝癌生长。
